Field of the Invention
The present disclosure relates to a water treatment system, especially to a water treatment system that detects occurrence of a fault in flocculation using a coagulant.
Description of Related Art
Conventionally, a coagulation-sedimentation method is employed in various fields of water treatment, including purification of water, sewage treatment, industrial water treatment, and industrial wastewater treatment, as a way to remove suspended matters that are present in water to be treated.
Such a coagulation-sedimentation method coagulates suspended matters that are present in water to be treated, sediments the resultant floc (i.e., clumps), and thus, removes the suspended matters from the water to be treated. Accordingly, favorable progress of flocculation using a coagulant is requisite for any water treatment technology employing the coagulation-sedimentation method.
Hence, as one water treatment system employing the coagulation-sedimentation method, a water treatment system that allows favorable flocculation by regulating a dosage of the coagulant has been proposed (refer to, for example, Patent Literatures 1 and 2).
In detail, Patent Literature 1 proposes a water treatment system including a floc image detection device that is disposed in the vicinity of an intake of a flocculation reservoir and that captures an image of the coagulated floc. By regulating a dosage of the coagulant based on the characteristics of the condition of flocculation grasped by data detected by the floc image detection device, the system proposed in Patent Literature 1 detects abnormal flocculation due to excess or deficiency in the dosage of the coagulant within a short period of time and corrects the dosage of the coagulant quickly.
Patent Literature 2 proposes a water treatment system that provides good-quality treated water even when the water quality of water to be treated is abruptly changed, by mixing raw water with a coagulant in an agitation tank, while measuring a particle diameter of floc and an ultra-violet absorbance of dissolved organic matters in the agitation tank at the same time, and by regulating a dosing rate of the coagulant to obtain a predetermined or larger particle diameter of floc and a predetermined or smaller ultra-violet absorbance of the dissolved organic matters.